As the game grows, your chance of getting season rewards is lowered.
Let me explain. If 100,000 people play a game, and only top 1,000 people get a reward. Then you have a 1% chance of getting a reward. Basically, the more people that play rocket bot royale, the lesser of a chance you have of getting season rewards. (sorry for the math lesson)
So here's what I suggest: Instead of having ranks based on top players, have it based off of top % of players.
Copper: top 8%
bronze: top 4%
sliver: top 2%
gold: top 1%
topaz: top 0.5%
amethyst: top 0.2%
emerald: top 0.1%
ruby: top 0.05%
diamond: top 0.025%
champion: top 0.010%
elite: top 0.005%
king: top player.
I probably did the math wrong, but this is just an example of the changes that would make season rewards more achievable.
(Or they could just add a very tiny reward for wood league. :p)